The following are related co-pending United States patent applications:
REMOVABLE SMALL FORM FACTOR FIBER OPTIC TRANSCEIVER MODULE CHASSIS, Serial No. 09/489,870, filed Jan. 20, 2000, by Scott M. Branch, David P. Gaio and William K. Hogan;
REMOVABLE LATCH AND BEZEL EMI GROUNDING FEATURE FOR FIBER-OPTIC TRANSCEIVERS, Serial No. 09/410,786, now U.S. Pat. No. 6,485,322, filed Oct. 1, 1999, by Scott M. Branch, David P. Gaio and William K. Hogan;
REMOVABLE SMALL FORM FACTOR FIBER OPTIC TRANSCEIVER MODULE AND ELECTROMAGNETIC RADIATION SHIELD, Serial No. 09/489,184, now U.S. Pat. No. 6,335,869, filed Jan. 20, 2000, by Scott M. Branch, David P. Gaio and William K. Hogan, which are incorporated herein in their entireties by this reference.
This invention relates to retaining mechanisms, and more specifically, to the latching mechanism utilized to retain an electrical interconnection and data signal conversion device in an installed condition, and thereby remain connected to circuitry within a computer or other electronic device.
Increasingly, computers are being connected to other computers and servers using fiber-optic cable or coaxial cable. Efficient connecting or networking of the computers and servers requires the interchangeability of transceiver modules utilized to connect the coaxial or fiber-optic cable to the electronics of the computer or servers. The interchangeability of the transceiver modules is necessary to accommodate those differences between the electrical signals carried over coaxial cable and the light pulse signals carried on the fiber-optic cable, and then to convert the signals between the electronic signals used by the computer and the optical signals carried on the fiber optic cable network.
A standard is in the process of being established for the interconnection interface and the transceiver modules so that the various component suppliers of the devices can supply modules which are completely interchangeable without regard to their sources.
A very significant problem concerning one proposed design for the interconnection interface relates to the latch itself, which retains the transceiver module within the computer housing and connects by the interconnection interface within the communication port. This latch device projects outside the exterior limits of the electronic system or computer housing. The latch device, where it is accessible and operable outside the computer housing, is subject to impact or large forces such as sufficient pulling of the connected cable to break the latch. Projecting from the communications port, the latch device is not protected from impact and breakage except that a transceiver module is resident in the communications port and substantially will cover or protect the latch member. Should the projecting latch member be broken, the computer or server may require significant service time and expense to return the communications or network connection to a functional and reliable condition. Disruption to the service of the computer or server, while the system is at least partially disassembled for repair or replacement of the latch device, is cause for numerous related costs for a computer or server; their operating and service personnel, and any related schedules. Once the latch device is broken or becomes non-functional, the connection between the computer or server and the network cable, either co-axial or fiber-optic, may be made but the connection is subject to inadvertent disconnection and poor reliability, thereby disrupting the flow of data signals over the network and thus interrupting the functions of the computer or server.
Where the latch is a part of the guide rail system of the communications port, a broken latch member may require the replacement of the guide rail system or, alternatively, the replacement of the electronic circuit board to which the guide rail system is soldered or affixed. Such replacements are not only very expensive but time consuming and can greatly limit the operability and reliability of the electronic system.
It is an object of the invention to reliably latch a transceiver module into a reliable electrical connection within a communications port of an electronic system.
It is another object of the invention to provide an inexpensive and reliable latch for a transceiver module.
It is an additional object of the invention to provide the capability of removing and replacing the latch member without replacing the much more expensive transceiver module.
It is a further object of the invention to eliminate the need for a latch that protrudes unprotected from a communications port of an electronic system, thereby reducing the damage potential to the system from breakage of the latch.
It is still another object of the invention to maintain a reliable connection between the computer or server and the transceiver module inserted into a connecting port.
It is a still further object of the invention to minimize the inconvenience and expense of replacing broken or damaged latch members.
It is still an additional object of the invention that the removable and replaceable latch be the weakest component in the latching system to protect the transceiver module and the electronic system from damage from excessive forces applied to a communications data cable.
It is still another object of the invention to eliminate the need for skilled service personnel to replace broken latches on the transceiver modules that couple with the communications port of an electronic system.
It is still another object of the invention to provide a simple procedure for the operator to replace the latch member of a transceiver module.
It is a still further object of the invention to provide a retention member that breaks within a designed force range in order to prevent damage to any related expensive devices and as well as be operator-replaceable.
A transceiver module for connecting electronic circuitry of an electronic system is a device which incorporates transceiver subassemblies. A transceiver subassembly receives electronic signals from the computer and converts those electronic signals to light pulse signals corresponding to the electronic signals for transmission over the network. The transceiver subassembly similarly will receive light pulse signals over fiber optic cable and convert the light signals to electrical signals for transmission to the computer. The transceiver subassemblies are connected to the network by a fiber optic cable connector, which is insertable into a transceiver module resident in a communications port of an electronic system. The transceiver module must be maintained in the communication port to insure reliable transmission of the optical signals on the fiber optic cable to the computer or server system. Similarly, a transceiver module capable of accepting and transmitting electronic signals over coaxial cable also may be inserted into the communications port of the computer whenever coaxial cable is used in the network.
An electronic or opto-electronic transceiver module is latched into position in the communications port by a latch disposed on the underside of the module; the module is manually unlatched as a latch tab is depressed. Depression of the latch tab will disengage a latch surface on the latch from a latch surface on a portion of the interconnection interface device, the system housing or the electromagnetic radiation shielding of the electronic system.
The latch is pivotally disposed on the transceiver module and biased to a latching position by a spring finger which is integrally formed as part of the latch. The latch, latch release tab, and spring are preferably integrally molded of a plastic.
Camming surfaces may be incorporated into the structure of the latch arm of the latch to cause movement of the latch arm during insertion of the transceiver module and latch into the electronic system. Further camming surfaces and projections may be formed into the latch arm structure to insure the latching surface of the latch arm is disposed juxtaposed to the latching surface on the interconnection interface device to establish a latching relationship and to maintain such relationship whether the coaxial or fiber optic cable connectors are resident within and connected to the transceiver module. Thus, the cable connectors must be removed before the transceiver module can be unlatched and removed from the electronic system.
Through adjustments of size and material, the latch is designed to be weaker than either the communications port hardware or the transceiver hardware. The latch is then sacrificed and replaced anytime the communications port, transceiver module, and communications data cable are stressed by excessive force applied to the cable. The replacement latch is snapped onto the transceiver module and the transceiver module is thereby returned to serviceability.